[Gluster-users] Replication not working on server hang

David Saez Padros david at ols.es
Fri Aug 28 14:37:10 UTC 2009


> NFS doesn't offer the options that GlusterFS does, so comparing 1:1 
> doesn't really make sense.

i agree, but i was not comparing features, what i wanted to point is
that this failure did never happen when using nfs and that it almost
always happen when using glusterfs. I you just consider nfs not
being very reliable, then it's even better for comparing against
glusterfs in that situation.

> There is no legitimate reason at all that the underlying file system 
> should lock up as a result of this. For some file systems, there is a 
> hang, not a lock up, until some critical section of the disk or in 
> memory representation is finished being worked on. I understand that 
> ext3 removing a large file is an example of something that might trigger 
> this for a period.

i don't think that this is a hang on the file system itself, another
user reported the same problem on another file system type and it's
very unlikely that both file systems had the same problem. Also i have
the problem with a ext3 file system which is very mature. I will say
that is more likely that the failure is in the driver, the kernel itself
or even in glusterfs than in the file system itself. The fact that this
bug does not appear when using the file system directly or through nfs
make glusterfs the most obvious candidate.

> It's not a simple problem to solve. But, it should be solved.

right, i'm also a developer and can understand that some developers
may see some bug reports as a personal attack, but the ones in this
list (at least me) see glusterfs as a good thing (that why we are
using it) and we are not attacking the software or the authors, we
are just reporting annoying situations that we feel should be
corrected. Bug reports that this ones should be investigated and
workarounds should be found so glusterfs volumes will be able to
tolerate this 'other software' faults gracefully

Best regards ...

    David Saez Padros                http://www.ols.es
    On-Line Services 2000 S.L.       telf    +34 902 50 29 75

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